Watched that on TV, it's ridiculous what ppl had put into those things! You could buy cars at the cost of those things. I know they font have many rules but is this rig gonna be legal? I thought it was an ATV/UTV event, and also, are you building it to look like a RZR?
Check out Lowrangeoffroad.com, petroworks.com, and roadlessgear.com for parts
also since it's gonna be a real mud bogger you may want to look at ISKY Torquer Cam and maybe an MSD ignition coil. Also Pace setter headers I've heard good things from.
I have a samurai and from what I'm told the ARB Air Lockers are the best for your buck. But stick with stock axles because apparently they don't make good HD axles for the rear.
I'll probably get bashed for some of my suggestions IF anyone else ever replies, but like I said they're just suggestions, you have to make the decisions.